Fire prevention system



March 12, 1935. HUNTER r AL 1,993,788

FIRE PREVENTION SYSTEM Filed NOV. 22, 1932 3 Sheets-Sheet l March 12, 1935. HUNTER ET AL 1,993,788

I FIRE. PREVENTION SYSTEM Filed Nov. 22, 1932 3 Sheets-Sheet 2 Eg g" Igwe'ntors li'vllaEffiuuh'z' CIwsterWJahnsou March 12, 1935. l. E. HUNTER ET AL FIRE PREVENTION SYSTEM 5 Sheets-Sheet 3 Filed NOV. 22, 1932 may mm film M 1m; m 8 I 1 A km W Eu. 0 Nut .6 nhw N N m I W L e W o o W. h b .Q NN N 5 N O matic detection has seemed impossible. For exalarm system.

Patented Mar.12, 1635 4 I V v 1,993,788

UNITED STATES PATENT OFFICE 1,993,788 FIRE PREVENTION SYSTEM Irvin E. Hunter, East Braintree, and Chester W. Johnson, Weymouth, Mass.

Application November 22, 1932, Serial No. 643,888 4 Claims. (01. 177-311) In the prevention of fire hazards and particureference numerals are employed to indicate corlarly in the precombustion stage of fire developresponding parts, and in the drawings: ment, there has been recognized for a long time Fig. 1 is a front elevation of the detection or the potential warning value of smoke fumes, but central station cabinet. most of the present systems of smoke detection Fig. 2 is a view from the left of the special cabiin practical use depend on sight or smell and net as shown in Fig. 1, with casing partly broken hence involve the factor of human error, failure away. or neglect. Fig. 3 is a similar view from the right of Fig. 1.

Under certain conditions mechanical or auto- Fig. 4 is a detail of a section of the vent and ample, on shipboard where multiple holds are Fig. 5 is a face view of the collector vent funnel loaded or in the process of being filled by grain, with the thermal unit encased, and

cement, ore or like friable binder, there is a defi- Fig. 6 is a diagrammatic view of the wiring nite dust factor. This is common also on land. system.

As the fire hazard at dock is really a more seri- The illustrative equipment shown in the drawous one than at sea, the loading period is of much ing consists of a collector system comprising tubes concern. The presence of unorganized loading 2 run on ceilings or below decks to all rooms, comworkers is a fire factor not under the check and partments or holds that are or might be dan r control of an organized crew on duty. spots.

The dust problem is also important on land in Spaced alon t e t b s are t e col ectors 1 of all sorts of buildings whether residences, offices, inverted fuimel or bell shape into which the surfactories or stores. Dust, soot or other accumurounding air is on uously drawn so that any lative film forming air impurities are common in sm k v n fr m a s all l a sm uld rin different places and 'at differing times. These will be caught and sucked into and through the even if slight and intermittent tend to accumulate tube of the Systema d b source of false 13mg w. p Suction is maintained by a pump F preferably The use of the photoelectric cell has lbng been o a d w the rest o the detection apparatus indicated as a logical basis of smoke detection. at the m' Station which 011 Shipboard w l However, the important emciency of light b.. be the pilot house or like place of authority and scurance by such means has been nullified among Source f emergency The P p F is P other causes by the common occurrence of dust 3 continuously p n or other media present in the air and tending to while 0111 System is essentially 8 Smoke deform films on parts th t t be kept, t standard tector, it combines with it a thermal auxiliary transparency. For this we utilize the collectors 1 as casings for Such conditions together with those necessarily thermostats 4 which are supported by scre ns 6 involved comprise the problem. Our concept is Over the collector mouthsbased on a simple and efilcient system of control The collector tubfis 2 are Supported Principaland mechanism to Solve it ly by hangers 5 slightly spaced from the cell- While marine conditions are of specific impormg oFher Point of elevatmh to which the smoke wo rise.

tance and generally illustrative, the ordinary fire hazard is equally present. on l we therefore The thermostats 4 have their contact members connected each with one of a pair of electrical wish to be considered as Operating within an conductors preferably in armoured cables 3 and reasonable lines of activities on land aswell as in protected relation These are Supported in at sea.

the hangers 5 one on each side of the conductor Aqcordmg to another phase of concept 2 and connect with an audible or visible signal Provlde our System for the detectmn gasessuch as a bell or red light (not shown) or both Many gases are M5 5 P 9 both Such a collector and alarm line is inconspicuand on account 01 then nrma1 mvlsiblhty ous and self protecting and can beeconomically stitute a great menace especially in conjunction installed, moved or added t as desired, with fi These and other features We Provide The various collector tubes 2 are connected for by simp e and ec iv y t m a d aro ato a manifold on the intake tube R of the pump tus which we so combine as to safeguard against F. As shown in Fig. 1 the pump F is mounted all emergencies. in a cabinet being directly coupled to a variable Throughout the specification and drawings like speed motor G, a transformer H and binding posts Y are indicated at the left of the motor. Variable resistors J J J are also mounted on the cabinet panel together with the auxiliary relay K, the cell relay M and the filament selector relay N and safety relay N.

The pump F draws up through the collector funnels and discharges through an exhaust tube S into a filter E. Its end is carried well down toward the filter bottom and preferably perforated. From the filter an exhaust tube T having a relief valve V leads to the smoke chamber B which is provided with a vent tube U.

The relief valve V is independent of the vent tube -U and permits excess quantities of air or smoke to be collected and pumped so that the smoke chamber is always fully supplied. Thus when the pump is speeded up the smoke laden struction.

The lamp house is provided with a double source of light. As shown in Fig. 1 this may be a pair of bulbs or as indicated in the wiring diagram in Fig. 6 may be a single bulb with a double filament. In either case upon the failure of one light source the other automatically comes into operation and at the same time operates a signal call for replacement. This is substantially in accordancewith our prior application Serial No. 611,220, filed May 13, 1932.

Our filter E is charged with finely divided material suchas crushed stone coated with an adhesive tacky dust arresting material, such as non-drying oil, or thin tar mixture having a softener resistant to drying. The filter bed thus formed has been found by experiments effectively to arrest all ordinary dust but readily to permit the passage of smoke therethrough, this being due presumably to ordinary dust particles being considerably larger than the infinitesimally small particles of carbon comprising smoke.

Other experiments have demonstrated that if the filter is supplied with water instead of oil or the like, dust is arrested and smoke is permitted to pass.

At Q we have indicated a perforated container covering the end of the exhaust tube T. In this container we provide a dry material reactive with the suspected invisible gas to make it visible as a dark or colored fume capable of obscuring the light in the smoke chamber B and thus operating the device in the same manner as the smoke itself if present.

In the electric circuit 14 of the photronic cell C is a relay 15 which operates a switch 16 located in a circuit 17 provided with an auxiliary relay 18. The circuit 1'7 has a booster battery 19 therein and the auxiliary relay actuates a switch 20 which closes the circuit with the line 21 from the main switch 22 with the wire 23 leading to a signal 24 located at some convenient point to give warning when the apparatus indicates that a firee1eCtr-iBfi7y'"WhiCh is indicated as having an alternating current of 110 volw. By means of the transformer 26, the voltage in the wire 25 leading to the filaments 12, 13 is reduced to some suitable low voltage such as ten volts.

In the line 25 is a variable resistance 27 which is used to adjust the lamp for the proper illumination. The line 28 leads from the transformer 26 to a safety relay 29 and from the safety relay 29 to a wire 30 leads to two test switches 21 and 32. The safety relay 29 is controlled by a switch 33 adapted to make and break the circuit in the wire line 17. The test switch 31 is connected to the filament 12 by a wire 34 in'which is a filament selector relay 35.

This selector relay 35 has associated therewith a switch 36 in the wire line 37 between the test switch 32 and the filament (or lamp) 13 and in this line 37 is a variable resistance '38 which may and when the filament 12 is in commission the filament selector relay 35 will be open. Should the filament 12 burn out no current will flow through the filament selector relay 35 and this relay 35 will actuate the contact points of the switch 36 to allow the current to pass through the filament 13.

The contacts on the photoelectric cell C and auxiliary relays are always open except when the light beams are interrupted by smoke entering the chamber B disposed between the light source and photoelectric cell.

Should both filaments or lamps burn out, or if power is interrupted for any other reason, the contact of switch 33 connected to the safety relay 29 will open and thus prevent the operation of the auxiliary relay l8 and the apparatus will remain out of commission until a new lamp 11 is installed in place of that burnt out. During this time, however, the thermal alarm is effective as the pump is kept running so that thermal alarm while combined with and a part of the smoke detector system may be in a sense considered an independent auxiliary and be kepton all day when the smoke detector is not usually needed.

During the day or when the building is occupied by workmen, the switch 22 is open and no current flows to the lamp 11, but when the workmen leave the building the main switch 22 is closed permitting the electric current to fiow through the various wire lines to the projecting lamp 11.

Each filament or lamp is tested by means of the test switches 31 and 32 to ascertain if both are in working condition. The light beams in the lamp 11 will be directed into the photocell unit 0 and the entire apparatus is ready for action in case of a fire.

The lamp or lamps and the lenses 1) of the smoke chamber B and 10 must be kept clean by brushes or cloth manually moved over the faces of the lenses.

What we therefore claim and desire to secure by Letters Patent is:-

1. Means for utilizing smoke emanating from a fire to detect the presence of the fire, said means comprising a photoelectric cell, means providing a source of light spaced from said cell and having a light beam falling thereon, an electric alarm system under the control of said cell, said system including means whereby the alarm is maintained inactive when the light strikes the cell and is rendered active when the light is obscured or is reduced a predetermined amount in intensity, means for conducting and inducing a flow of air and smoke, it the latter is present, from a location of possible fire through the space between said cell and said source 0! light so that if smoke is present the light is obscured or reduced in intensity sufliciently to cause the cell to render the alarm system active, and a filter in the air and smoke conducting means between said space and the location of possible fire, said filter being efiective to permit the passage of smoke and to effect the removal from the air of dust of a character which, if present in the air, would obscure.

or reduce the intensity of the light sumciently to cause the cell to render the alarm active.

2. Fire detection means as set forth in claim 1 in which a chamber having a smaller outlet than inlet and transparent windows for the passage of the light is provided in the air and smoke conducting means at a point between the source of light and the cell for the accumulation of smoke.

3. Fire detection means as set forth in claim 1 including means in the air and smoke conducting means reactive with invisible gases to render them visible as a dark or colored fume capable of affecting the cell in'the same way as smoke.

4. Fire detection means as set forth in claim 1 including means in the air and smoke conducting means reactive with invisible gases to render them visible as a dark or colored fume capable of affecting the cell in the same way as smoke, said reactive means being disposed to react with the gases after their passage through the filter and prior to their passage through the space between the cell and the source of light.

CHESTER W. JOHNSON. 

